imbecility vs stupidity

imbecility

noun
  • Something imbecilic; a stupid action, behaviour, etc. 

  • The quality of being imbecile; weakness; feebleness, especially of mind. 

stupidity

noun
  • An act that is stupid. 

  • The property of being stupid. 

How often have the words imbecility and stupidity occurred in a corpus of books? (source: Google Ngram Viewer )